BUILT-IN WOLFRAM LANGUAGE SYMBOL
is an option for Trace and related functions which specifies whether to include preceding expressions on the evaluation chain that contains the pattern form sought.
- TraceBackward->True includes the first expression on the evaluation chain that contains form.
- TraceBackward->All includes all expressions before form on the evaluation chain that contains form.
- TraceBackward allows you to see the previous forms that an expression had during an evaluation.
A recursive definition for finding Fibonacci numbers:
Show only what additions of positive integers are required:
Show the beginning of the evaluation chain that leads to each addition:
Show all intermediate evaluations that led to each addition: